1. Field of the Invention
The present invention relates to a high density connector and particularly to a connector assembly utilizing such high density connectors to create a unique connection interface.
2. Description of Related Art
With electronic device miniaturization and high signal integrity electronic communications becoming more prevalent, the optimization of space usage becomes a significant factor in connector design.
In card edge connectors, it is known to arrange contacts in two levels. U.S. Pat. No. 5,052,936 issued on Oct. 1, 1991 to Biechler et al. exemplifies such a connector. In this design, two arrays of aligned contact members for interfacing either side of a board or card edge are insert molded to a lower subassembly housing which in turn is assembled to an upper housing. The board or card edge is provided with an upper level of contact pads and a lower level of contact pads. When the board or card edge is inserted into the housing, the lower level of contact pads electrically connect with a first array of contact members of the connector and the upper level of contact pads electrically connect with a second array of contact members.
U.S. Pat. No. 7,104,848 issued on Sep. 12, 2006 to Chou et al. discloses an USB (Universal Serial Bus) related electrical connector comprising a plug and a socket mated with the plug. The plug has an array of front contact pins and an array of rear contact pins. The socket also has an array of front contact pins and an array of rear contact pins for electrically connecting with the rear and front contact pins of the plug, respectively.
The above two patents do not disclose how their contact arrangement in two (e.g. upper and lower) levels or in two (e.g. front and rear) arrays can be implemented in a tight space, such as in mezzanine backplane applications where, for example, a daughter board is to be interfaced with a mother board through two interconnected connectors associated with individual (printed circuit) boards. As a further example of one level only interconnection or interface, U.S. Pat. No. 6,981,883 issued on Jan. 3, 2006 to Raistrick et al. discloses an impedance controlled electrical connector, particularly a mezzanine connector, which comprises insert molded leadframe assembly in a split configuration.
U.S. Pat. No. 5,904,581 issued on May 18, 1999 to Pope et al. discloses an electrical interconnection system comprising a female connector and a male connector mated with the female connector. Each of the male and female connectors comprises body walls with contact elements positioned on opposite side faces of the body wall. The contact element may have straight or angled end segments. Generally, for a mating pair of contact elements of the two connectors, one of the mated contact elements has a straight end segment and the other contact element has an angled end segment. Unlike the upper and lower aligned contact members seen in the card edge connector of the mentioned '936 patent, the contact elements on a specific side face of the body wall in this patent does not show aligned contact arrangement nor imply interconnection occurring at two levels.
U.S. Pat. No. 6,371,773 issued on Apr. 16, 2002 to Crofoot et al. discloses a high density interconnect system used in association with printed circuit boards, circuit cards, back panels and other like substrates. Conceiving a need to reduce interference, cross-talk and similar signal degration, and especially to do so in relatively small size connectors while providing relatively high signal density, the interconnect system comprises electrical connector modules each having a plurality of signal conductors substantially parallel within a first plane and a reference conductor element made of a single piece of sheet metal. The reference conductor element includes a plurality of first reference conductors substantially parallel to one another and interspersed between the signal conductors and at least part of which are in the first plane and a plurality of second reference conductors within a second plane which is offset from and substantially parallel to the first plane. The second reference conductor is aligned with the signal conductor in a direction perpendicular to the plane of the connector module. However, when the connector modules of two mating connector portions are mated, curved contact ends of mating signal conductors make a hermaphrodite mating while associated second reference conductors only shield beside the mated signal conductor but not touch each other.
U.S. patent application Ser. No. 11/818,100 filed on Jun. 13, 2007 and assigned to the same assignee as the present invention also discloses a USB-related contact mating interface which occurs at two levels. However, like above-mentioned prior art patents, there is not any discussion as to how the unique two-level mating interface can be exploited or modified to be used in high density connector applications, in combination with other feature or features as will be apparent from the detailed description and claims below.